Direct synthesis and properties of monomeric and dimeric MnIII–salen complexes tuned by tetrahalocadmate anions

Two novel compounds [Mn(salen)(dmf)2]3[Mn(salen)(dmf)(H2O)][CdCl4]2·H2O (1) and {[Mn(salen)(CH3OH)]2}[Mn(salen)(CH3OH)2]2[CdI4]2 (2) have been synthesised via interaction of manganese metal and cadmium halide with in situ generated salen ligand (salen = N,N′-ethylene-bis-salicylideneaminato) in non-aqueous (dmf, CH3OH) solutions. X-ray structure analysis reveals that in solid state 1 contains mononuclear MnIII–salen species, whilst in 2 both monomeric and out-of-plane dimeric MnIII–salen complexes are present. Moreover, in 2 the monomeric units are linked by H-bonds, forming other dimers. Equilibrium between monomeric and dimeric units in solutions of 1 and 2 was found by ESI mass-spectrometry. The magnetic measurements of 2 demonstrated antiferromagnetic interactions between MnIII centres.